Tropical Storm Erin brushes Cape Verdes

My analysis of the tropical Atlantic based on this evening’s GOES unenhanced imagery. Red dashed lines represent the rough locations of tropical waves. 1. Tropical Storm Erin moving away from the Cape Verdes. 2. Tropical Wave that the National Hurricane Center has given a 50% chance for development in 48hours.

The National Hurricane Center found that Tropical Storm Erin formed overnight, prompting tropical storm warnings for the Cape Verde islands. There, winds reached about 35mph with gusts likely over tropical storm force. Since then, Erin has moved away to the west of the Cape Verde islands. The environment that Erin is moving into on its current west-northwest track is only slightly favorable for tropical cyclones and so, after a strengthening phase tomorrow, Erin should begin to level off in intensity, or even weaken. Typical dry, stable eastern Atlantic air, combined with sea surface temperatures that are near the threshold for tropical cyclones should keep Erin from strengthening quickly out to 5 days. Regardless, Erin is more than a week away from the longitude of the Lesser Antilles islands, and most long range model indications suggest that this storm should track north of those islands. Erin should be monitored by Bermuda, if it survives the Eastern and Central Atlantic, it may be a long range (day 7-11) threat to Bermuda if it recurves around the western side of the Bermuda-Azores high.

Additionally, an organizing tropical wave over the Western Caribbean moved ashore in the Yucatan Peninsula bringing heavy rains. The National Hurricane Center gives this wave a medium 50% chance of becoming a tropical cyclone in the Gulf of Mexico in the next 48hours as of 9pm tonight Bermuda time. The long term track of this system is very uncertain as it has not concentrated into a tropical cyclone – something it may never do. As the wave approaches a front stalling to its north over the lower Mississippi Valley, the environment could become too unfavorable for a tropical cyclone to form because of strengthening southerly and southwesterly winds ahead of the front. However, this should draw the convergence and moisture associated with this system towards the northern Gulf Coast regardless of tropical cyclone formation – this could lead to a flooding situation as rainfall is enhanced along a stationary front. If this becomes a tropical cyclone, it is not likely to become a threat to Bermuda.